Over the last two weeks my desktop has seemingly all of a sudden become noticeably less stable: frequent BSODs (all with different error messages but all of which were related to memory), difficulties performing basic application installs/uninstalls, random application misbehavior, and occasional "forgetting" to load drivers at boot-up (for instance, on one boot, windows wouldn't load the graphics drivers and the resolution would be terrible; reboot, everything's fine again. wash, rinse, repeat).

The only common thread I could think of was RAM, so I booted into memtest86+. Within minutes it had found thousands of errors; over the course of the night, it found 125,000+ errors in 4 passes.

So I started swapping them out and rotating the DIMMs. I have four sticks of memory for four slots, each 2 GB. Starting with the stick in the first slot, I tested it by itself in slots 1, 2, 3, and 4, going for at least two passes in memtest before moving it to the next slot. No errors reported anywhere.

Next, I tried the stick that had originally been in slot 2 and put it back in slot 2 by itself. No errors. Same with stick 3 into slot 3 by itself. No errors. Same with stick 4. No errors.

Then I tried sticks 3 & 4 in the last two slots. Nothing. Sticks 2, 3, & 4 in the last three slots. No errors. I am now running all four again - the exact configuration that produced the cascading memory errors the first time - and so far it's been running for almost 30 minutes (well into the thousands of errors from the previous scan), and it hasn't reported a single error.

I recall I had been fiddling with a memory fan that clips onto the northbridge, situating itself just on top of the chips. It's possible in messing around with it that I knocked one of the DIMMs slightly out of place. Thanks!
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MagsolDec 14 '09 at 3:47